Where is the best place to hide from a tornado if I'm outdoors?
If there is no other shelter around, storm experts usually recommend that you find a trench or ditch if a tornado is approaching and you don't have time to get to a tornado shelter or basement. (It is not a good idea to hide under a freeway overpass, as debris can still easily blow inside and prove deadly.) Some people believe that you are safer if you are in a mountain valley, because the mountains will block tornadoes. Actually, tornadoes have swept through valleys, and they have even touched on mountain peaks. Tornadoes have been recorded in the Teton wilderness area at elevations of more than 10,000 feet (3,000 meters), and during the super tornado outbreak of 1974 many tornadoes struck high areas of the Appalachians.
There is also a myth that standing near a river is a safe place to be during a tornado warning. Again, there have been a number of incidents during which tornadoes have been spotted near, or even crossing, streams and rivers as big as the Mississippi and Missouri. It is not unheard of to learn of boats that have been sunk while sailing down a river when a tornado struck.
Which month is the most dangerous for tornadoes in the United States?
According to one study, May is the most dangerous month for tornadoes in the United States, with an average of 329, while February's average is the safest with only three. In another study the months December and January were usually the safest, and the months having the greatest number of tornadoes were April, May, and June. In February, tornado frequency begins to increase. February tornadoes tend to occur in the central Gulf states; in March the center of activity moves eastward to the southeastern Atlantic states, where tornado activity peaks in April. In May the center of activity is in the southern Plains states; in June this moves to the northern Plains and Great Lakes area (into western New York). The most costly outbreak of tornadoes occurred in May 1999, when at least 74 tornadoes touched down in less than 48 hours in Oklahoma and Kansas, including an F5 on the outskirts of Oklahoma City causing $1.1 billion in damage.
What is a gustnado?
Seen near thunderstorm outflows, a gustnado is a weak vortex that does not touch the clouds. Gustnadoes usually do little more damage than breaking some tree branches and overturning lawn furniture.
What are waterspouts?
Often associated with tropical cyclones, waterspouts are tornadoes that can form over a body of water. Instead of sucking up dust and debris, the funnel is visible because of the water it carries. While they tend to be weaker than tornadoes, they can still be lethal and have been known to destroy small boats and cause damage to larger vessels. The most common place to find waterspouts in the United States is off the coast of southern Florida.
What is a landspout?
A landspout is, technically, a tornado, albeit a very weak one. Landspouts generally form from non-supercell storms. Despite tending to be less strong than other tornadoes, they have been known to cause fatalities and should still be avoided at all costs.
A waterspout is seen off the coast of the Florida Keys. (photo by Joseph Golden, NOAA)
What are dust devils?
These columns of brown, dust-filled air, which can rise dozens of feet, are not as evil as the name suggests. They are caused by warm air rising on dry, clear days. Winds associated with dust devils can reach up to 60 miles (96.5 kilometers) per hour and cause some damage. There have been reports of dust devils as tall as 5,000 feet (1,500 meters). They are generally not as destructive as tornadoes and usually die out pretty quickly, though some have been known to displace as much as 50 tons (4,500 kilograms) of dust and light debris. One of the biggest dust devils ever recorded was seen in Bonneville Salt Flats in Utah. It was hundreds of feet tall, and it continued on its way for about 40 miles (65 kilometers).
What is a steam devil?
In the Arctic (and, less often, Antarctic, or any other place where conditions are right), cold air passing over warm areas of water can cause steam to rise, and when a whirlwind sweeps in at the same time, this steam or fog forms small steam devils.
Are there other types of tornado-like whirlwinds?
Certainly. Smoke from forest fires and ash and steam from volcanoes can often stir about in vortices that look like weak tornadoes.